#!/usr/bin/ruby
require 'time'

syslog = '/var/log/syslog'
Dir.chdir('/var/www/html/rrd')
rrd = 'cpi.rrd'
$VERBOSE = true if STDERR.tty?

lavg = wifi = temp = now = nil
File.open(syslog){|fp|
  last = nil
  for line in fp
    begin
    next unless / cherrypie loadrrd / =~ line
    rescue ArgumentError
    end
    last = line
  end
  STDERR.puts last if $VERBOSE
  lavg = $1.to_f if /load=([.0-9]+)/ =~ last
  wifi = $1.to_i if /wifi=([.0-9]+)/ =~ last
  if / t=([-.0-9]+)\/([-.0-9]+)\/([-.0-9]+)/ =~ last
    temp = ($1.to_i+$2.to_i+$3.to_i)/300.0
  end
  if /(\w\w\w .\d \d\d:\d\d:\d\d|\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d\.\d+[-+]\d\d:\d\d)/ =~ last
    stime = $1
    time = Time.parse(stime)
    now = time.to_i
    STDERR.puts time.to_s if $VERBOSE
  end
}

exit if now.nil?

if not File.exist?(rrd) then
  cmd = %W<
    #{rrd}
    DS:load:GAUGE:600:U:U
    RRA:AVERAGE:0.5:1:512 RRA:AVERAGE:0.5:12:512 RRA:AVERAGE:0.5:288:512
    DS:wifi:GAUGE:600:U:U
    RRA:AVERAGE:0.5:1:512 RRA:AVERAGE:0.5:12:512 RRA:AVERAGE:0.5:288:512
    DS:temp:GAUGE:600:U:U
    RRA:AVERAGE:0.5:1:512 RRA:AVERAGE:0.5:12:512 RRA:AVERAGE:0.5:288:512
  >
  STDERR.puts "+ rrdcreate #{cmd.join(' ')}" if $VERBOSE
  system("rrdcreate", *cmd)
end

cmd = [rrd, '-s', [now,lavg,wifi,temp].join(':')]
STDERR.puts "+ rrdupdate #{cmd.join(' ')}" if $VERBOSE
system("rrdupdate", *cmd)

STDOUT.reopen("/dev/null")

cmd = %W<
graph cpiload.png -t cherrypie.load
  DEF:load=#{rrd}:load:AVERAGE CDEF:cload=load,100,* LINE1:cload#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)

cmd = %W<
graph cpiloadd10.png --end now --start now-864000s -t cherrypie.load
  DEF:load=#{rrd}:load:AVERAGE CDEF:cload=load,100,* LINE1:cload#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)

cmd = %W<
graph cpitempd10.png --end now --start now-864000s -t cherrypie.temp
  DEF:temp=#{rrd}:temp:AVERAGE CDEF:ctemp=temp,0.1,* LINE1:ctemp#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)

cmd = %W<
graph cpiwifi.png -t cherrypie.wifi
  DEF:wifi=#{rrd}:wifi:AVERAGE LINE1:wifi#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)

cmd = %W<
graph cpiwifid10.png --end now --start now-864000s -t cherrypie.wifi.10days
  DEF:wifi=#{rrd}:wifi:AVERAGE LINE1:wifi#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)

cmd = %W<
graph cpitemp.png -t cherrypie.temp
  DEF:temp=#{rrd}:temp:AVERAGE CDEF:ctemp=temp,0.1,* LINE1:ctemp#FF0000
>
STDERR.puts "+ rrdtool #{cmd.join(' ')}" if $VERBOSE
system("rrdtool", *cmd)